Justification:
This species is listed as Critically Endangered due to a severe reduction in population, estimated to be greater than 80% over the past 3 generations (18 years) due to destruction of habitat.

Saguinus oedipus occurs in northwestern Colombia between the Río Atrato and the lower Río Cauca (west of the Río Cauca and the Isla de Mompos) and Magdalena, in the Departments of Atlantico, Sucre, Cordoba, and western Bolivar, northwestern Antiquoia (from the Uraba region, west of the Río Cauca) and northeastern Choco, east of the Río Atrato, from sea level up to 1,500 m (Hernández-Camacho and Cooper 1976, Hershkovitz 1977, Hernández-Camacho and Defler 1989, Mast et al. 1993 ).

The south-western boundary of the cotton-top's range has not been clearly identified. Mast et al. (1983) suggested that it may extend to Villa Arteaga on the Río Sucio (Hershkovitz 1977), which included reports of Cotton-top Tamarins in Los Katios National Park. However, Barbosa et al. (1988) were unable to find any evidence of Cotton-top Tamarins in this area nor in Los Katios, where they observed only Saguinus geoffroyi. Neyman (1981) did not find evidence of cotton-top tamarins in the upper Sinu.

Groups have been seen in the Islas del Rosario and Tayrona National Park in the Sierra Nevada de Santa Marta (Mast et al. 1993; A. Savage and L.H. Giraldo pers. obs.). However, these populations were founded by captive animals that were released into the area (Mast et al. 1993) and these remnant populations are here considered as outside of the historic range of the species.

In the late 1960s and early 1970s, 20,000-30,000 individuals were exported to the United States for biomedical research (Hernández-Camacho and Cooper 1976). Current population estimates for the species are 6,000 individuals (approximately 2,000 mature individuals).

This species occurs in humid forest in the south to dry deciduous forest in the north; recorded from primary and secondary forests. Known at altitudes up to 400 m, but could occur in higher elevations (to 1,500 m) in the upper valley of the Río Sinu (Defler 2004).

Marmosets and tamarins are distinguished from the other monkeys of the New World by their small size, modified claws rather than nails on all digits except the big toe, the presence of two as opposed to three molar teeth in either side of each jaw, and by the occurrence of twin births. They eat fruits, flowers, nectar, plant exudates (gums, saps, latex) and animal prey (including frogs, snails, lizards, spiders and insects). Marmosets have morphological and behavioural adaptations for gouging trees trunks, branches and vines of certain species to stimulate the flow of gum, which they eat, and in some species form a notable component of the diet. The dentition of the tamarins (Saguinus and Leontopithecus) does not provide for gouging and they eat gums only when readily available.

Tamarins live in extended family groups of between four and 15 individuals, but usually 2-8. Saguinus oedipus lives in groups of 2-9. Neyman (1977, 1979) observed groups of 3-13, and Savage et al. (1996a,b) observed reproductively active groups that ranged in size from 3-6. Generally, only one female per group breeds during a particular breeding season.

Saguinus oedipus occurs in an area of intensive colonization and forest loss. Neyman (1978) estimated that 75% of the original distribution of S. oedipus had been cleared for agriculture and pasture, and that the remainder of its range was represented by small isolated forest patches along with its main stronghold, the Paramillo National Natural Park of 460,000 ha. Cerquera (1985) reported on the threats regarding the construction of two hydroelectric dams, Urra I and Urra II, on the Ríos Sinu and San Jorge, in the south of its range. Urra II is sited within the Paramillo National Natural Park and is expected to flood more than 54,000 ha of primary and secondary forest, within what is considered to be the last major stronghold for the species.

The three protected areas where they occur have lost a significant portion of their forests (Barbosa et al. 1988). Paramillo has lost approximately 42% of its original forested habitat and Montes de Maria and Los Colorados lost 70 and 71%, respectively. To date, almost 200,000 ha of the original forested areas within protected boundaries of the parks and reserves dedicated to Cotton-top Tamarin conservation efforts have been lost. This suggests, therefore, that there is less than 2,600 km² that will be protected in perpetuity for Cotton-top Tamarins by the Colombian Ministerio del Medio Ambiente. Although these areas are protected, they continue to suffer from the pressure of the growing local populations to extract resources or clear areas for agricultural activities.

Defler (1994, 2004; pp.196-201) discusses the conservation status and threats to this species (see also Defler and Rodríguez-Mahecha 2003, Defler et al. 2003).

Legally protected in Colombia since 1969. Major threat in the past was export for the pet trade, zoos and biomedical research, but export was banned in 1974. Listed on CITES Appendix I.

There are three protected areas where Saguinus oedpipus occurs: Paramillo National Natural Park (460,000 ha), decreed in 1977; Los Colorados Fauna and Flora Sanctuary (1,000 ha) decreed in 1977; and Reserva Forestal Cerro de Coraza-Monte de Marja (7,460 ha) decreed in 1983. They were also introduced to Tayrona National Natural Park in 1974 (Defler 1994).

Proyecto Tití, a conservation programme for the Cotton-top Tamarin in Colombia, was established in 1987 to begin the first long-term field study on this species in collaboration with Colombian biologists, educators, NGO's and government authorities (INDERENA, Ministerio del Medio Ambiente) (Savage 1988, 1993, 1995, 1996, 1997; Savage et al. 1996a,b, 1997, 2001a,b). Initial research focused on understanding the factors influencing reproductive strategies of Cotton-top Tamarins, but it quickly grew into a comprehensive conservation programme including educational efforts, capacity building, training Colombian students, development of economic alternatives, and the development of an agricultural training programme to decrease the pressure on the forest by local communities (Savage and Giraldo 1990; Savage et al. 1990, 1996, 1997).

In addition to the studies of Cotton-top Tamarins in the field, there has been a major and comprehensive assessment of the remaining habitat within the historic distribution of the Cotton-top Tamarin in Colombia, along with surveys to assess population numbers remaining. This information has provided important insights into the long-term viability of this population given the current rate of habitat destruction.